Devices, such as mobile phones, can include microphones to receive sound and generate a corresponding analog electrical signal. Such devices can also include analog-to-digital converters, which convert the analog electrical signal provided by the device's microphone to digital information.
Devices, such as mobile phones can include speakers to generate sound corresponding to an electrical signal. Such devices can also include digital-to-analog converters, which convert a digital signal to an analog electrical signal. Such an analog electrical signal can be provided to the device's speaker, through an amplifier, to produce sound.